.fa{
    width: 200px;
    height: 200px;
    background-color: pink;
    .son{
        width: 100px;
        height: 100px;
        background-color: powderblue;
    }
}
.box1{
    width: 100px;
    height: 100px;
    background-image: url('./images/vue.png');
    background-repeat: no-repeat;
    background-size:100% 100%;
}
.box2{
    width: 100px;
    height: 100px;
    background-image: url('./images/file_type_react.png');
    background-repeat: no-repeat;
    background-size:100% 100%;
}
#lanBtn{
    background-color: aquamarine;
    width: 50px;
    height: 50px;
}